The 32-year-old scored twice, assisted once, and sent a message to Jurgen Klinsmann while setting the all-time MLS goals record.
The Galaxy were on the board within two minutes, and Donovan was the man who set it up. The USA snub sent in a great free kick, which Leonardo headed home from six yards out.
The record-breaking goal came five minutes into the second half. Donovan started the move with a pass to Robbie Keane in the box. The Irishman squared across the face of goal for the onrushing Donovan, who was left with a tap-in for his first goal of the season, and 135th of his career.
The Union were down three after a weak Sheanon Williams back pass was pounced on by Keane. The Irishman held off Williams as he slipped the ball through Zac MacMath’s legs and into the back of the net.
Donovan made it two for good measure late on, after a Philadelphia turnover led to Keane getting the ball with plenty of space, and finding Donovan in the box. The recently crowned MLS all-time leading scorer cut back and finished low for career goal number 136.
The Union grabbed a late consolation when another U.S. cut, Maurice Edu, scored from the penalty spot.